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Diffstat (limited to 'lib/libkvm/kvm_amd64.c')
-rw-r--r--lib/libkvm/kvm_amd64.c360
1 files changed, 360 insertions, 0 deletions
diff --git a/lib/libkvm/kvm_amd64.c b/lib/libkvm/kvm_amd64.c
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+++ b/lib/libkvm/kvm_amd64.c
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+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1989, 1992, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software developed by the Computer Systems
+ * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
+ * BG 91-66 and contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+
+/*
+ * AMD64 machine dependent routines for kvm. Hopefully, the forthcoming
+ * vm code will one day obsolete this module.
+ */
+
+#include <sys/param.h>
+#include <sys/endian.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <vm/vm.h>
+#include <kvm.h>
+
+#include <limits.h>
+
+#include "kvm_private.h"
+#include "kvm_amd64.h"
+
+struct vmstate {
+ size_t phnum;
+ GElf_Phdr *phdr;
+ amd64_pml4e_t *PML4;
+};
+
+/*
+ * Translate a physical memory address to a file-offset in the crash-dump.
+ */
+static size_t
+_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
+{
+ struct vmstate *vm = kd->vmst;
+ GElf_Phdr *p;
+ size_t n;
+
+ if (kd->rawdump) {
+ *ofs = pa;
+ return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
+ }
+
+ p = vm->phdr;
+ n = vm->phnum;
+ while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
+ p++, n--;
+ if (n == 0)
+ return (0);
+ *ofs = (pa - p->p_paddr) + p->p_offset;
+ return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
+}
+
+static void
+_amd64_freevtop(kvm_t *kd)
+{
+ struct vmstate *vm = kd->vmst;
+
+ if (vm->PML4)
+ free(vm->PML4);
+ free(vm->phdr);
+ free(vm);
+ kd->vmst = NULL;
+}
+
+static int
+_amd64_probe(kvm_t *kd)
+{
+
+ return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
+ !_kvm_is_minidump(kd));
+}
+
+static int
+_amd64_initvtop(kvm_t *kd)
+{
+ struct kvm_nlist nl[2];
+ amd64_physaddr_t pa;
+ kvaddr_t kernbase, kernphys;
+ amd64_pml4e_t *PML4;
+ int found = 0;
+
+ kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
+ if (kd->vmst == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate vm");
+ return (-1);
+ }
+ kd->vmst->PML4 = 0;
+
+ if (kd->rawdump == 0) {
+ if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
+ &kd->vmst->phdr) == -1)
+ return (-1);
+
+ for (size_t i = 0; i < kd->vmst->phnum; i++) {
+ if (kd->vmst->phdr[i].p_type == PT_DUMP_DELTA) {
+ /* Account for the 2M hole at KERNBASE. */
+ kernphys = kd->vmst->phdr[i].p_paddr -
+ kd->vmst->phdr[i].p_align;
+ kernbase = kd->vmst->phdr[i].p_vaddr;
+
+ found = 1;
+ break;
+ }
+ }
+ }
+
+ if (found == 0) {
+ nl[0].n_name = "kernbase";
+ nl[1].n_name = 0;
+
+ if (kvm_nlist2(kd, nl) != 0) {
+ _kvm_err(kd, kd->program, "bad namelist - no kernbase");
+ return (-1);
+ }
+
+ nl[0].n_name = "kernphys";
+ nl[1].n_name = 0;
+
+ /* XXX
+ * Relocatable kernels can still be loaded at 2M.
+ */
+ if (kvm_nlist2(kd, nl) != 1) {
+ _kvm_err(kd, kd->program, "cannot determine kernphys");
+ return (-1);
+ }
+
+ kernphys = 0;
+ kernbase = nl[0].n_value;
+ }
+
+ nl[0].n_name = "KPML4phys";
+ nl[1].n_name = 0;
+
+ if (kvm_nlist2(kd, nl) != 0) {
+ _kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
+ return (-1);
+ }
+ if (kvm_read2(kd, (nl[0].n_value - kernbase + kernphys), &pa,
+ sizeof(pa)) != sizeof(pa)) {
+ _kvm_err(kd, kd->program, "cannot read KPML4phys");
+ return (-1);
+ }
+ pa = le64toh(pa);
+ PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE);
+ if (PML4 == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate PML4");
+ return (-1);
+ }
+ if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) {
+ _kvm_err(kd, kd->program, "cannot read KPML4phys");
+ free(PML4);
+ return (-1);
+ }
+ kd->vmst->PML4 = PML4;
+ return (0);
+}
+
+static int
+_amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
+{
+ struct vmstate *vm;
+ amd64_physaddr_t offset;
+ amd64_physaddr_t pdpe_pa;
+ amd64_physaddr_t pde_pa;
+ amd64_physaddr_t pte_pa;
+ amd64_pml4e_t pml4e;
+ amd64_pdpe_t pdpe;
+ amd64_pde_t pde;
+ amd64_pte_t pte;
+ kvaddr_t pml4eindex;
+ kvaddr_t pdpeindex;
+ kvaddr_t pdeindex;
+ kvaddr_t pteindex;
+ amd64_physaddr_t a;
+ off_t ofs;
+ size_t s;
+
+ vm = kd->vmst;
+ offset = va & AMD64_PAGE_MASK;
+
+ /*
+ * If we are initializing (kernel page table descriptor pointer
+ * not yet set) then return pa == va to avoid infinite recursion.
+ */
+ if (vm->PML4 == NULL) {
+ s = _kvm_pa2off(kd, va, pa);
+ if (s == 0) {
+ _kvm_err(kd, kd->program,
+ "_amd64_vatop: bootstrap data not in dump");
+ goto invalid;
+ } else
+ return (AMD64_PAGE_SIZE - offset);
+ }
+
+ pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1);
+ pml4e = le64toh(vm->PML4[pml4eindex]);
+ if ((pml4e & AMD64_PG_V) == 0) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid");
+ goto invalid;
+ }
+
+ pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1);
+ pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t));
+
+ s = _kvm_pa2off(kd, pdpe_pa, &ofs);
+ if (s < sizeof(pdpe)) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found");
+ goto invalid;
+ }
+ if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) {
+ _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe");
+ goto invalid;
+ }
+ pdpe = le64toh(pdpe);
+ if ((pdpe & AMD64_PG_V) == 0) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid");
+ goto invalid;
+ }
+
+ if (pdpe & AMD64_PG_PS) {
+ /*
+ * No next-level page table; pdpe describes one 1GB page.
+ */
+ a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK);
+ s = _kvm_pa2off(kd, a, pa);
+ if (s == 0) {
+ _kvm_err(kd, kd->program,
+ "_amd64_vatop: 1GB page address not in dump");
+ goto invalid;
+ } else
+ return (AMD64_NBPDP - (va & AMD64_PDPMASK));
+ }
+
+ pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1);
+ pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t));
+
+ s = _kvm_pa2off(kd, pde_pa, &ofs);
+ if (s < sizeof(pde)) {
+ _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found");
+ goto invalid;
+ }
+ if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) {
+ _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde");
+ goto invalid;
+ }
+ pde = le64toh(pde);
+ if ((pde & AMD64_PG_V) == 0) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid");
+ goto invalid;
+ }
+
+ if (pde & AMD64_PG_PS) {
+ /*
+ * No final-level page table; pde describes one 2MB page.
+ */
+ a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK);
+ s = _kvm_pa2off(kd, a, pa);
+ if (s == 0) {
+ _kvm_err(kd, kd->program,
+ "_amd64_vatop: 2MB page address not in dump");
+ goto invalid;
+ } else
+ return (AMD64_NBPDR - (va & AMD64_PDRMASK));
+ }
+
+ pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1);
+ pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t));
+
+ s = _kvm_pa2off(kd, pte_pa, &ofs);
+ if (s < sizeof(pte)) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found");
+ goto invalid;
+ }
+ if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
+ _kvm_syserr(kd, kd->program, "_amd64_vatop: read");
+ goto invalid;
+ }
+ if ((pte & AMD64_PG_V) == 0) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid");
+ goto invalid;
+ }
+
+ a = (pte & AMD64_PG_FRAME) + offset;
+ s = _kvm_pa2off(kd, a, pa);
+ if (s == 0) {
+ _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump");
+ goto invalid;
+ } else
+ return (AMD64_PAGE_SIZE - offset);
+
+invalid:
+ _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
+ return (0);
+}
+
+static int
+_amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
+{
+
+ if (ISALIVE(kd)) {
+ _kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
+ return (0);
+ }
+ return (_amd64_vatop(kd, va, pa));
+}
+
+int
+_amd64_native(kvm_t *kd __unused)
+{
+
+#ifdef __amd64__
+ return (1);
+#else
+ return (0);
+#endif
+}
+
+static struct kvm_arch kvm_amd64 = {
+ .ka_probe = _amd64_probe,
+ .ka_initvtop = _amd64_initvtop,
+ .ka_freevtop = _amd64_freevtop,
+ .ka_kvatop = _amd64_kvatop,
+ .ka_native = _amd64_native,
+};
+
+KVM_ARCH(kvm_amd64);